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 2003 Prentice Hall, Inc. All rights reserved. 1 Chapter 14 – Graphical User Components Part 2 Outline 14.1 Introduction 14.2 JTextArea 14.3 Creating.

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Presentation on theme: " 2003 Prentice Hall, Inc. All rights reserved. 1 Chapter 14 – Graphical User Components Part 2 Outline 14.1 Introduction 14.2 JTextArea 14.3 Creating."— Presentation transcript:

1  2003 Prentice Hall, Inc. All rights reserved. 1 Chapter 14 – Graphical User Components Part 2 Outline 14.1 Introduction 14.2 JTextArea 14.3 Creating a Customized Subclass of JPanel 14.4 JPanel Subclass that Handles Its Own Events 14.5 JSlider 14.6 Windows: Additional Notes 14.7 Using Menus with Frames 14.8 JPopupMenu 14.9 Pluggable Look-and-Feel 14.10 JDesktopPane and JInternalFrame 14.11 JTabbedPane

2  2003 Prentice Hall, Inc. All rights reserved. 2 14.1 Introduction Advanced GUI components –Text areas –Sliders –Menus Multiple Document Interface (MDI) Advanced layout managers –BoxLayout –GridBagLayout

3  2003 Prentice Hall, Inc. All rights reserved. 3 14.2 JTextArea JTextArea –Area for manipulating multiple lines of text –extends JTextComponent, which declares common methods for JTextFields, JTextAreas, and other text-based GUI components

4  2003 Prentice Hall, Inc. All rights reserved. Outline TextAreaDemo.ja va Line 16 Lines 18-24 1 // Fig. 14.1: TextAreaDemo.java 2 // Copying selected text from one textarea to another. 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 public class TextAreaDemo extends JFrame { 8 private JTextArea textArea1, textArea2; 9 private JButton copyButton; 10 11 // set up GUI 12 public TextAreaDemo() 13 { 14 super( "TextArea Demo" ); 15 16 Box box = Box.createHorizontalBox(); 17 18 String string = "This is a demo string to\n" + 19 "illustrate copying text\nfrom one textarea to \n" + 20 "another textarea using an\nexternal event\n"; 21 22 // set up textArea1 23 textArea1 = new JTextArea( string, 10, 15 ); 24 box.add( new JScrollPane( textArea1 ) ); 25 Create Box container for organizing GUI components, reference: Section 14.12 Populate JTextArea with String, then add to Box

5  2003 Prentice Hall, Inc. All rights reserved. Outline TextAreaDemo.ja va Line 36 Lines 44-45 26 // set up copyButton 27 copyButton = new JButton( "Copy >>>" ); 28 box.add( copyButton ); 29 copyButton.addActionListener( 30 31 new ActionListener() { // anonymous inner class 32 33 // set text in textArea2 to selected text from textArea1 34 public void actionPerformed( ActionEvent event ) 35 { 36 textArea2.setText( textArea1.getSelectedText() ); 37 } 38 39 } // end anonymous inner class 40 41 ); // end call to addActionListener 42 43 // set up textArea2 44 textArea2 = new JTextArea( 10, 15 ); 45 textArea2.setEditable( false ); 46 box.add( new JScrollPane( textArea2 ) ); 47 48 // add box to content pane 49 Container container = getContentPane(); 50 container.add( box ); // place in BorderLayout.CENTER 51 Instantiate uneditable JTextArea When user presses JButton, textArea1 ’s highlighted text is copied into textArea2

6  2003 Prentice Hall, Inc. All rights reserved. Outline TextAreaDemo.ja va 52 setSize( 425, 200 ); 53 setVisible( true ); 54 55 } // end constructor TextAreaDemo 56 57 public static void main( String args[] ) 58 { 59 TextAreaDemo application = new TextAreaDemo(); 60 application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 61 } 62 63 } // end class TextAreaDemo

7  2003 Prentice Hall, Inc. All rights reserved. 7 14.3 Creating a Customized Subclass of JPanel Extend JPanel to create new components –Dedicated drawing area Method paintComponent of class JComponent Method setOpaque (boolean isOpaque) –If isOpaque is true, the component paints every pixel within its bounds. Otherwise, the component may not paint some or all of its pixels, allowing the underlying pixels to show through. –The default value of this property is false for JComponent. However, the default value for this property on most standard JComponent subclasses (such as JButton and JTree) is look-and-feel dependent.

8  2003 Prentice Hall, Inc. All rights reserved. Outline CustomPanel.jav a Line 8 Line 11 Line 25 1 // Fig. 14.2: CustomPanel.java 2 // A customized JPanel class. 3 import java.awt.*; 4 import javax.swing.*; 5 6 public class CustomPanel extends JPanel { 7 public final static int CIRCLE = 1, SQUARE = 2; 8 private int shape; 9 10 // use shape to draw an oval or rectangle 11 public void paintComponent( Graphics g ) 12 { 13 super.paintComponent( g ); 14 15 if ( shape == CIRCLE ) 16 g.fillOval( 50, 10, 60, 60 ); 17 else if ( shape == SQUARE ) 18 g.fillRect( 50, 10, 60, 60 ); 19 } 20 21 // set shape value and repaint CustomPanel 22 public void draw( int shapeToDraw ) 23 { 24 shape = shapeToDraw; 25 repaint(); 26} 27 28 } // end class CustomPanel Store integer representing shape to draw Override method paintComponent of class JComponent to draw oval or rectangle. Remember JFrame and JApplet use the method paint. Method repaint calls method paintComponent

9  2003 Prentice Hall, Inc. All rights reserved. Outline CustomPanelTest.java Lines 18-19 1 // Fig. 14.3: CustomPanelTest.java 2 // Using a customized Panel object. 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 public class CustomPanelTest extends JFrame { 8 private JPanel buttonPanel; 9 private CustomPanel myPanel; 10 private JButton circleButton, squareButton; 11 12 // set up GUI 13 public CustomPanelTest() 14 { 15 super( "CustomPanel Test" ); 16 17 // create custom drawing area 18 myPanel = new CustomPanel(); 19 myPanel.setBackground( Color.GREEN ); 20 21 // set up squareButton 22 squareButton = new JButton( "Square" ); 23 squareButton.addActionListener( 24 Instantiate CustomPanel object and set background to green

10  2003 Prentice Hall, Inc. All rights reserved. Outline CustomPanelTest.java Line 30 Line 45 25 new ActionListener() { // anonymous inner class 26 27 // draw a square 28 public void actionPerformed( ActionEvent event ) 29 { 30 myPanel.draw( CustomPanel.SQUARE ); 31 } 32 33 } // end anonymous inner class 34 35 ); // end call to addActionListener 36 37 circleButton = new JButton( "Circle" ); 38 circleButton.addActionListener( 39 40 new ActionListener() { // anonymous inner class 41 42 // draw a circle 43 public void actionPerformed( ActionEvent event ) 44 { 45 myPanel.draw( CustomPanel.CIRCLE ); 46 } 47 48 } // end anonymous inner class 49 50 ); // end call to addActionListener 51 When user presses circleButton, draw circle on CustomPanel When user presses squareButton, draw square on CustomPanel

11  2003 Prentice Hall, Inc. All rights reserved. Outline CustomPanelTest.java Line 54 52 // set up panel containing buttons 53 buttonPanel = new JPanel(); 54 buttonPanel.setLayout( new GridLayout( 1, 2 ) ); 55 buttonPanel.add( circleButton ); 56 buttonPanel.add( squareButton ); 57 58 // attach button panel & custom drawing area to content pane 59 Container container = getContentPane(); 60 container.add( myPanel, BorderLayout.CENTER ); 61 container.add( buttonPanel, BorderLayout.SOUTH ); 62 63 setSize( 300, 150 ); 64 setVisible( true ); 65 66 } // end constructor CustomPanelTest 67 68 public static void main( String args[] ) 69 { 70 CustomPanelTest application = new CustomPanelTest(); 71 application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 72 } 73 74 } // end class CustomPanelTest Use GridLayout to organize buttons

12  2003 Prentice Hall, Inc. All rights reserved. 12 14.4 JPanel Subclass that Handles Its Own Events JPanel –Does not support conventional events e.g., events offered by buttons, text areas, etc. –Capable of recognizing lower-level events e.g., mouse events, key events, etc. –Self-contained panel Listens for its own mouse events

13  2003 Prentice Hall, Inc. All rights reserved. Outline SelfContainedPa nel.java Line 16 Lines 23-24 1 // Fig. 14.4: SelfContainedPanel.java 2 // A self-contained JPanel class that handles its own mouse events. 3 package com.deitel.jhtp5.ch14; 4 5 import java.awt.*; 6 import java.awt.event.*; 7 import javax.swing.*; 8 9 public class SelfContainedPanel extends JPanel { 10 private int x1, y1, x2, y2; 11 12 // set up mouse event handling for SelfContainedPanel 13 public SelfContainedPanel() 14 { 15 // set up mouse listener 16 addMouseListener( 17 18 new MouseAdapter() { // anonymous inner class 19 20 // handle mouse press event 21 public void mousePressed( MouseEvent event ) 22 { 23 x1 = event.getX(); 24 y1 = event.getY(); 25 } 26 Self-contained JPanel listens for MouseEvent s Save coordinates where user pressed mouse button

14  2003 Prentice Hall, Inc. All rights reserved. Outline SelfContainedPa nel.java Lines 30-31 Line 40 Lines 47-48 27 // handle mouse release event 28 public void mouseReleased( MouseEvent event ) 29 { 30 x2 = event.getX(); 31 y2 = event.getY(); 32 repaint(); 33 } 34 35 } // end anonymous inner class 36 37 ); // end call to addMouseListener 38 39 // set up mouse motion listener 40 addMouseMotionListener( 41 42 new MouseMotionAdapter() { // anonymous inner class 43 44 // handle mouse drag event 45 public void mouseDragged( MouseEvent event ) 46 { 47 x2 = event.getX(); 48 y2 = event.getY(); 49 repaint(); 50 } 51 Save coordinates where user released mouse button, then repaint Self-contained JPanel listens for when mouse moves Save coordinates where user dragged mouse, then repaint

15  2003 Prentice Hall, Inc. All rights reserved. Outline SelfContainedPa nel.java Lines 69-70 52 } // end anonymous inner class 53 54 ); // end call to addMouseMotionListener 55 56 } // end constructor SelfContainedPanel 57 58 // return preferred width and height of SelfContainedPanel 59 public Dimension getPreferredSize() 60 { 61 return new Dimension( 150, 100 ); 62 } 63 64 // paint an oval at the specified coordinates 65 public void paintComponent( Graphics g ) 66 { 67 super.paintComponent( g ); 68 69 g.drawOval( Math.min( x1, x2 ), Math.min( y1, y2 ), 70 Math.abs( x1 - x2 ), Math.abs( y1 - y2 ) ); 71 } 72 73 } // end class SelfContainedPanel Draw ovalThe preferred size of the component when laying out the component as part of a GUI

16  2003 Prentice Hall, Inc. All rights reserved. Outline SelfContainedPa nelTest.java Lines 17-18 1 // Fig. 14.5: SelfContainedPanelTest.java 2 // Creating a self-contained subclass of JPanel that processes 3 // its own mouse events. 4 import java.awt.*; 5 import java.awt.event.*; 6 import javax.swing.*; 7 8 import com.deitel.jhtp5.ch14.SelfContainedPanel; 9 10 public class SelfContainedPanelTest extends JFrame { 11 private SelfContainedPanel myPanel; 12 13 // set up GUI and mouse motion event handlers for application window 14 public SelfContainedPanelTest() 15 { 16 // set up a SelfContainedPanel 17 myPanel = new SelfContainedPanel(); 18 myPanel.setBackground( Color.YELLOW ); 19 20 Container container = getContentPane(); 21 container.setLayout( new FlowLayout() ); 22 container.add( myPanel ); 23 Instantiate SelfContaintedPanel object and set background to yellow

17  2003 Prentice Hall, Inc. All rights reserved. Outline SelfContainedPa nelTest.java Line 25 Lines 30-41 24 // set up mouse motion event handling 25 addMouseMotionListener( 26 27 new MouseMotionListener() { // anonymous inner class 28 29 // handle mouse drag event 30 public void mouseDragged( MouseEvent event ) 31 { 32 setTitle( "Dragging: x=" + event.getX() + 33 "; y=" + event.getY() ); 34 } 35 36 // handle mouse move event 37 public void mouseMoved( MouseEvent event ) 38 { 39 setTitle( "Moving: x=" + event.getX() + 40 "; y=" + event.getY() ); 41 } 42 43 } // end anonymous inner class 44 45 ); // end call to addMouseMotionListener 46 47 setSize( 300, 200 ); 48 setVisible( true ); 49 50 } // end constructor SelfContainedPanelTest Register anonymous-inner-class object to handle mouse motion events Display a String in title bar indicating x-y coordinate where mouse-motion event occurred

18  2003 Prentice Hall, Inc. All rights reserved. Outline SelfContainedPa nelTest.java 51 52 public static void main( String args[] ) 53 { 54 SelfContainedPanelTest application = new SelfContainedPanelTest(); 55 application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 56 } 57 58 } // end class SelfContainedPanelTest

19  2003 Prentice Hall, Inc. All rights reserved. 19 14.5 JSlider JSlider –Enable users to select from a range of integer values –Several features Tick marks (major and minor) –Major: –Minor (1/10): PageUp 、 PageDown Snap-to ticks: –Positioning the thumb between two tick marks causes the thumb to snap to closest tick mark Orientation (horizontal and vertical)

20  2003 Prentice Hall, Inc. All rights reserved. 20 Fig. 14.6 JSlider component with horizontal orientation thumb tick mark

21  2003 Prentice Hall, Inc. All rights reserved. Outline OvalPanel.java Line 14 Line 18 1 // Fig. 14.7: OvalPanel.java 2 // A customized JPanel class. 3 import java.awt.*; 4 import javax.swing.*; 5 6 public class OvalPanel extends JPanel { 7 private int diameter = 10; 8 9 // draw an oval of the specified diameter 10 public void paintComponent( Graphics g ) 11 { 12 super.paintComponent( g ); 13 14 g.fillOval( 10, 10, diameter, diameter ); 15 } 16 17 // validate and set diameter, then repaint 18 public void setDiameter( int newDiameter ) 19 { 20 // if diameter invalid, default to 10 21 diameter = ( newDiameter >= 0 ? newDiameter : 10 ); 22 repaint(); 23 } 24 Draw filled oval of diameter Set diameter, then repaint

22  2003 Prentice Hall, Inc. All rights reserved. Outline OvalPanel.java 25 // used by layout manager to determine preferred size 26 public Dimension getPreferredSize() 27 { 28 return new Dimension( 200, 200 ); 29 } 30 31 // used by layout manager to determine minimum size 32 public Dimension getMinimumSize() 33 { 34 return getPreferredSize(); 35 } 36 37 } // end class OvalPanel

23  2003 Prentice Hall, Inc. All rights reserved. Outline SliderDemo.java Lines 18-19 Lines 22-23 1 // Fig. 14.8: SliderDemo.java 2 // Using JSliders to size an oval. 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 import javax.swing.event.*; 7 8 public class SliderDemo extends JFrame { 9 private JSlider diameterSlider; 10 private OvalPanel myPanel; 11 12 // set up GUI 13 public SliderDemo() 14 { 15 super( "Slider Demo" ); 16 17 // set up OvalPanel 18 myPanel = new OvalPanel(); 19 myPanel.setBackground( Color.YELLOW ); 20 21 // set up JSlider to control diameter value 22 diameterSlider = 23 new JSlider( SwingConstants.HORIZONTAL, 0, 200, 10 ); 24 diameterSlider.setMajorTickSpacing( 10 ); 25 diameterSlider.setPaintTicks( true ); 26 Instantiate an OvalPanel object and set background to yellow Instantiate a horizontal JSlider object with min. value of 0, max. value of 200 and initial thumb location at 10

24  2003 Prentice Hall, Inc. All rights reserved. Outline SliderDemo.java Line 28 Line 35 27 // register JSlider event listener 28 diameterSlider.addChangeListener( 29 30 new ChangeListener() { // anonymous inner class 31 32 // handle change in slider value 33 public void stateChanged( ChangeEvent e ) 34 { 35 myPanel.setDiameter( diameterSlider.getValue() ); 36 } 37 38 } // end anonymous inner class 39 40 ); // end call to addChangeListener 41 42 // attach components to content pane 43 Container container = getContentPane(); 44 container.add( diameterSlider, BorderLayout.SOUTH ); 45 container.add( myPanel, BorderLayout.CENTER ); 46 47 setSize( 220, 270 ); 48 setVisible( true ); 49 50 } // end constructor SliderDemo 51 Register anonymous ChangeListener object to handle JSlider events When user accesses JSlider, set OvalPanel ’s diameter according to JSlider value

25  2003 Prentice Hall, Inc. All rights reserved. Outline SliderDemo.java 52 public static void main( String args[] ) 53 { 54 SliderDemo application = new SliderDemo(); 55 application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 56 } 57 58 } // end class SliderDemo

26  2003 Prentice Hall, Inc. All rights reserved. 26 14.6 Windows: Additional Notes JFrame –Windows with title bar and border –Subclass of java.awt.Frame Subclass of java.awt.Window –Heavyweight component (platform dependent) –Three constants for setDefaultCloseOperation methods when user closes window WindowConstant.DISPOSE_ON_CLOSE (resource release) WindowConstant.DO_NOTHING_ON_CLOSE (program checks) WindowConstant.HIDE_ON_CLOSE JFrame.EXIT_ON_CLOSE –Methods setVisible, setSize, setLocation –WindowListener has 7 methods: windowActivated, windowClosed, windowClosing, …

27  2003 Prentice Hall, Inc. All rights reserved. 27 14.7 Using Menus with Frames Menus –Allows for performing actions with cluttering ( 混亂的 ) GUI –Contained by menu bar JMenuBar (a subclass of JComponent) –Comprised of menu items JMenuItem (a subclass of javax.swing.AbstractButton) –JCheckBoxMenuItem –JRadioButtonMenuItem ButtonGroup

28  2003 Prentice Hall, Inc. All rights reserved. Outline MenuTest.java Line 22 1 // Fig. 14.9: MenuTest.java 2 // Demonstrating menus 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 public class MenuTest extends JFrame { 8 private final Color colorValues[] = 9 { Color.BLACK, Color.BLUE, Color.RED, Color.GREEN }; 10 private JRadioButtonMenuItem colorItems[], fonts[]; 11 private JCheckBoxMenuItem styleItems[]; 12 private JLabel displayLabel; 13 private ButtonGroup fontGroup, colorGroup; 14 private int style; 15 16 // set up GUI 17 public MenuTest() 18 { 19 super( "Using JMenus" ); 20 21 // set up File menu and its menu items 22 JMenu fileMenu = new JMenu( "File" ); 23 fileMenu.setMnemonic( 'F' ); 24 Instantiate File JMenu

29  2003 Prentice Hall, Inc. All rights reserved. Outline MenuTest.java Line 26 Lines 36-38 Line 46 25 // set up About... menu item 26 JMenuItem aboutItem = new JMenuItem( "About..." ); 27 aboutItem.setMnemonic( 'A' ); 28 fileMenu.add( aboutItem ); 29 aboutItem.addActionListener( 30 31 new ActionListener() { // anonymous inner class 32 33 // display message dialog when user selects About... 34 public void actionPerformed( ActionEvent event ) 35 { 36 JOptionPane.showMessageDialog( MenuTest.this, 37 "This is an example\nof using menus", 38 "About", JOptionPane.PLAIN_MESSAGE ); 39 } 40 41 } // end anonymous inner class 42 43 ); // end call to addActionListener 44 45 // set up Exit menu item 46 JMenuItem exitItem = new JMenuItem( "Exit" ); 47 exitItem.setMnemonic( 'x' ); 48 fileMenu.add( exitItem ); 49 exitItem.addActionListener( 50 Instantiate About… JMenuItem to be placed in fileMenu When user selects About… JMenuItem, display message dialog with appropriate text Instantiate Exit JMenuItem to be placed in fileMenu

30  2003 Prentice Hall, Inc. All rights reserved. Outline MenuTest.java Line 56 Line 64 Line 69 51 new ActionListener() { // anonymous inner class 52 53 // terminate application when user clicks exitItem 54 public void actionPerformed( ActionEvent event ) 55 { 56 System.exit( 0 ); 57 } 58 59 } // end anonymous inner class 60 61 ); // end call to addActionListener 62 63 // create menu bar and attach it to MenuTest window 64 JMenuBar bar = new JMenuBar(); 65 setJMenuBar( bar ); 66 bar.add( fileMenu ); 67 68 // create Format menu, its submenus and menu items 69 JMenu formatMenu = new JMenu( "Format" ); 70 formatMenu.setMnemonic( 'r' ); 71 72 // create Color submenu 73 String colors[] = { "Black", "Blue", "Red", "Green" }; 74 When user selects Exit JMenuItem, exit system Instantiate JMenuBar to contain JMenu s Instantiate Format JMenu

31  2003 Prentice Hall, Inc. All rights reserved. Outline MenuTest.java Line 75 Lines 78-79 Line 96 75 JMenu colorMenu = new JMenu( "Color" ); 76 colorMenu.setMnemonic( 'C' ); 77 78 colorItems = new JRadioButtonMenuItem[ colors.length ]; 79 colorGroup = new ButtonGroup(); 80 ItemHandler itemHandler = new ItemHandler(); 81 82 // create color radio button menu items 83 for ( int count = 0; count < colors.length; count++ ) { 84 colorItems[ count ] = 85 new JRadioButtonMenuItem( colors[ count ] ); 86 colorMenu.add( colorItems[ count ] ); 87 colorGroup.add( colorItems[ count ] ); 88 colorItems[ count ].addActionListener( itemHandler ); 89 } 90 91 // select first Color menu item 92 colorItems[ 0 ].setSelected( true ); 93 94 // add format menu to menu bar 95 formatMenu.add( colorMenu ); 96 formatMenu.addSeparator(); 97 98 // create Font submenu 99 String fontNames[] = { "Serif", "Monospaced", "SansSerif" }; 100 Instantiate Color JMenu (submenu of Format JMenu ) Instantiate JRadioButtonMenuItem s for Color JMenu and ensure that only one menu item is selected at a time Separator places line between JMenuItem s

32  2003 Prentice Hall, Inc. All rights reserved. Outline MenuTest.java Line 101 Lines 104-105 101 JMenu fontMenu = new JMenu( "Font" ); 102 fontMenu.setMnemonic( 'n' ); 103 104 fonts = new JRadioButtonMenuItem[ fontNames.length ]; 105 fontGroup = new ButtonGroup(); 106 107 // create Font radio button menu items 108 for ( int count = 0; count < fonts.length; count++ ) { 109 fonts[ count ] = new JRadioButtonMenuItem( fontNames[ count ] ); 110 fontMenu.add( fonts[ count ] ); 111 fontGroup.add( fonts[ count ] ); 112 fonts[ count ].addActionListener( itemHandler ); 113 } 114 115 // select first Font menu item 116 fonts[ 0 ].setSelected( true ); 117 118 fontMenu.addSeparator(); 119 120 // set up style menu items 121 String styleNames[] = { "Bold", "Italic" }; 122 123 styleItems = new JCheckBoxMenuItem[ styleNames.length ]; 124 StyleHandler styleHandler = new StyleHandler(); 125 Instantiate Font JMenu (submenu of Format JMenu ) Instantiate JRadioButtonMenuItem s for Font JMenu and ensure that only one menu item is selected at a time

33  2003 Prentice Hall, Inc. All rights reserved. Outline MenuTest.java 126 // create style checkbox menu items 127 for ( int count = 0; count < styleNames.length; count++ ) { 128 styleItems[ count ] = 129 new JCheckBoxMenuItem( styleNames[ count ] ); 130 fontMenu.add( styleItems[ count ] ); 131 styleItems[ count ].addItemListener( styleHandler ); 132 } 133 134 // put Font menu in Format menu 135 formatMenu.add( fontMenu ); 136 137 // add Format menu to menu bar 138 bar.add( formatMenu ); 139 140 // set up label to display text 141 displayLabel = new JLabel( "Sample Text", SwingConstants.CENTER ); 142 displayLabel.setForeground( colorValues[ 0 ] ); 143 displayLabel.setFont( new Font( "Serif", Font.PLAIN, 72 ) ); 144 145 getContentPane().setBackground( Color.CYAN ); 146 getContentPane().add( displayLabel, BorderLayout.CENTER ); 147 148 setSize( 500, 200 ); 149 setVisible( true ); 150 151 } // end constructor 152

34  2003 Prentice Hall, Inc. All rights reserved. Outline MenuTest.java Line 163 Lines 168 and 176 Lines 169 and 177- 178 153 public static void main( String args[] ) 154 { 155 MenuTest application = new MenuTest(); 156 application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 157 } 158 159 // inner class to handle action events from menu items 160 private class ItemHandler implements ActionListener { 161 162 // process color and font selections 163 public void actionPerformed( ActionEvent event ) 164 { 165 // process color selection 166 for ( int count = 0; count < colorItems.length; count++ ) 167 168 if ( colorItems[ count ].isSelected() ) { 169 displayLabel.setForeground( colorValues[ count ] ); 170 break; 171 } 172 173 // process font selection 174 for ( int count = 0; count < fonts.length; count++ ) 175 176 if ( event.getSource() == fonts[ count ] ) { 177 displayLabel.setFont( 178 new Font( fonts[ count ].getText(), style, 72 ) ); 179 break; 180 } Invoked when user selects JMenuItem Determine which font or color menu generated event Set font or color of JLabel, respectively

35  2003 Prentice Hall, Inc. All rights reserved. Outline MenuTest.java Line 192 Lines 197-202 181 182 repaint(); 183 184 } // end method actionPerformed 185 186 } // end class ItemHandler 187 188 // inner class to handle item events from check box menu items 189 private class StyleHandler implements ItemListener { 190 191 // process font style selections 192 public void itemStateChanged( ItemEvent e ) 193 { 194 style = 0; 195 196 // check for bold selection 197 if ( styleItems[ 0 ].isSelected() ) 198 style += Font.BOLD; 199 200 // check for italic selection 201 if ( styleItems[ 1 ].isSelected() ) 202 style += Font.ITALIC; 203 204 displayLabel.setFont( 205 new Font( displayLabel.getFont().getName(), style, 72 ) ); Invoked when user selects JCheckBoxMenuItem Determine new font style

36  2003 Prentice Hall, Inc. All rights reserved. Outline MenuTest.java 206 207 repaint(); 208 } 209 210 } // end class StyleHandler 211 212 } // end class MenuTest

37  2003 Prentice Hall, Inc. All rights reserved. 37 14.8 JPopupMenu Context-sensitive popup menus –JPopupMenu –Menu generated depending on which component is accessed

38  2003 Prentice Hall, Inc. All rights reserved. Outline PopupTest.java Line 23 1 // Fig. 14.10: PopupTest.java 2 // Demonstrating JPopupMenus 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 public class PopupTest extends JFrame { 8 private JRadioButtonMenuItem items[]; 9 private final Color colorValues[] = 10 { Color.BLUE, Color.YELLOW, Color.RED }; 11 private JPopupMenu popupMenu; 12 13 // set up GUI 14 public PopupTest() 15 { 16 super( "Using JPopupMenus" ); 17 18 ItemHandler handler = new ItemHandler(); 19 String colors[] = { "Blue", "Yellow", "Red" }; 20 21 // set up popup menu and its items 22 ButtonGroup colorGroup = new ButtonGroup(); 23 popupMenu = new JPopupMenu(); 24 items = new JRadioButtonMenuItem[ 3 ]; 25 Instantiate JPopupMenu object

39  2003 Prentice Hall, Inc. All rights reserved. Outline PopupTest.java Lines 29-32 Lines 46 and 52 26 // construct each menu item and add to popup menu; also 27 // enable event handling for each menu item 28 for ( int count = 0; count < items.length; count++ ) { 29 items[ count ] = new JRadioButtonMenuItem( colors[ count ] ); 30 popupMenu.add( items[ count ] ); 31 colorGroup.add( items[ count ] ); 32 items[ count ].addActionListener( handler ); 33 } 34 35 getContentPane().setBackground( Color.WHITE ); 36 37 // declare a MouseListener for the window that displays 38 // a JPopupMenu when the popup trigger event occurs 39 addMouseListener( 40 41 new MouseAdapter() { // anonymous inner class 42 43 // handle mouse press event 44 public void mousePressed( MouseEvent event ) 45 { 46 checkForTriggerEvent( event ); 47 } 48 49 // handle mouse release event 50 public void mouseReleased( MouseEvent event ) 51 { 52 checkForTriggerEvent( event ); 53 } Create JRadioButtonMenuItem objects to add to JPopupMenu, 可 能有 2 個以上的 ButtonGroups Determine whether popup- trigger event occurred when user presses or releases mouse button

40  2003 Prentice Hall, Inc. All rights reserved. Outline PopupTest.java Lines 59-60 54 55 // determine whether event should trigger popup menu 56 private void checkForTriggerEvent( MouseEvent event ) 57 { 58 if ( event.isPopupTrigger() ) 59 popupMenu.show( 60 event.getComponent(), event.getX(), event.getY() ); 61 } 62 63 } // end anonymous inner clas 64 65 ); // end call to addMouseListener 66 67 setSize( 300, 200 ); 68 setVisible( true ); 69 70 } // end constructor PopupTest 71 72 public static void main( String args[] ) 73 { 74 PopupTest application = new PopupTest(); 75 application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 76 } 77 Show JPopupMenu if popup-trigger occurred

41  2003 Prentice Hall, Inc. All rights reserved. Outline PopupTest.java Line 82 Line 87 78 // private inner class to handle menu item events 79 private class ItemHandler implements ActionListener { 80 81 // process menu item selections 82 public void actionPerformed( ActionEvent event ) 83 { 84 // determine which menu item was selected 85 for ( int i = 0; i < items.length; i++ ) 86 if ( event.getSource() == items[ i ] ) { 87 getContentPane().setBackground( colorValues[ i ] ); 88 return; 89 } 90 } 91 92 } // end private inner class ItemHandler 93 94 } // end class PopupTest Invoked when user selects JRadioButtonMenuItem Determine which JRadioButtonMenuItem was selected, then set window background color

42  2003 Prentice Hall, Inc. All rights reserved. 42 14.9 Pluggable Look-and-Feel Pluggable look-and-feel –Change look-and-feel dynamically cross-platform Metal Microsoft Windows look-and-feel Motif look-and-feel –Flexible

43  2003 Prentice Hall, Inc. All rights reserved. Outline LookAndFeelDemo.java Line 9 1 // Fig. 14.11: LookAndFeelDemo.java 2 // Changing the look and feel. 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 public class LookAndFeelDemo extends JFrame { 8 private final String strings[] = { "Metal", "Motif", "Windows" }; 9 private UIManager.LookAndFeelInfo looks[]; 10 private JRadioButton radio[]; 11 private ButtonGroup group; 12 private JButton button; 13 private JLabel label; 14 private JComboBox comboBox; 15 16 // set up GUI 17 public LookAndFeelDemo() 18 { 19 super( "Look and Feel Demo" ); 20 21 Container container = getContentPane(); 22 23 // set up panel for NORTH of BorderLayout 24 JPanel northPanel = new JPanel(); 25 northPanel.setLayout( new GridLayout( 3, 1, 0, 5 ) ); 26 Hold installed look-and-feel information 第 3 、 4 參數指定 gap space

44  2003 Prentice Hall, Inc. All rights reserved. Outline LookAndFeelDemo.java 27 // set up label for NORTH panel 28 label = new JLabel( "This is a Metal look-and-feel", 29 SwingConstants.CENTER ); 30 northPanel.add( label ); 31 32 // set up button for NORTH panel 33 button = new JButton( "JButton" ); 34 northPanel.add( button ); 35 36 // set up combo box for NORTH panel 37 comboBox = new JComboBox( strings ); 38 northPanel.add( comboBox ); 39 40 // create array for radio buttons 41 radio = new JRadioButton[ strings.length ]; 42 43 // set up panel for SOUTH of BorderLayout 44 JPanel southPanel = new JPanel(); 45 southPanel.setLayout( new GridLayout( 1, radio.length ) ); 46 47 // set up radio buttons for SOUTH panel 48 group = new ButtonGroup(); 49 ItemHandler handler = new ItemHandler(); 50

45  2003 Prentice Hall, Inc. All rights reserved. Outline LookAndFeelDemo.java 51 for ( int count = 0; count < radio.length; count++ ) { 52 radio[ count ] = new JRadioButton( strings[ count ] ); 53 radio[ count ].addItemListener( handler ); 54 group.add( radio[ count ] ); 55 southPanel.add( radio[ count ] ); 56 } 57 58 // attach NORTH and SOUTH panels to content pane 59 container.add( northPanel, BorderLayout.NORTH ); 60 container.add( southPanel, BorderLayout.SOUTH ); 61 62 // get installed look-and-feel information 63 looks = UIManager.getInstalledLookAndFeels(); 64 65 setSize( 300, 200 ); 66 setVisible( true ); 67 68 radio[ 0 ].setSelected( true ); 69 70 } // end constructor LookAndFeelDemo 71 72 // use UIManager to change look-and-feel of GUI 73 private void changeTheLookAndFeel( int value ) 74 {

46  2003 Prentice Hall, Inc. All rights reserved. Outline LookAndFeelDemo.java Lines 77-78 75 // change look and feel 76 try { 77 UIManager.setLookAndFeel( looks[ value ].getClassName() ); 78 SwingUtilities.updateComponentTreeUI( this ); 79 } 80 81 // process problems changing look and feel 82 catch ( Exception exception ) { 83 exception.printStackTrace(); 84 } 85 } 86 87 public static void main( String args[] ) 88 { 89 LookAndFeelDemo application = new LookAndFeelDemo(); 90 application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 91 } 92 93 // private inner class to handle radio button events 94 private class ItemHandler implements ItemListener { 95 96 // process user's look-and-feel selection 97 public void itemStateChanged( ItemEvent event ) 98 { 99 for ( int count = 0; count < radio.length; count++ ) 100 Change look-and-feel

47  2003 Prentice Hall, Inc. All rights reserved. Outline LookAndFeelDemo.java 101 if ( radio[ count ].isSelected() ) { 102 label.setText( "This is a " + 103 strings[ count ] + " look-and-feel" ); 104 comboBox.setSelectedIndex( count ); 105 changeTheLookAndFeel( count ); 106 } 107 } 108 109 } // end private inner class ItemHandler 110 111 } // end class LookAndFeelDemo

48  2003 Prentice Hall, Inc. All rights reserved. 48 14.10 JDesktopPane and JInternalFrame Multiple document interface –Main (parent) window (JDesktopPane) –Child windows (JInternalFrame) –Switch freely among documents

49  2003 Prentice Hall, Inc. All rights reserved. Outline DesktopTest.jav a Line 8 1 // Fig. 14.12: DesktopTest.java 2 // Demonstrating JDesktopPane. 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 public class DesktopTest extends JFrame { 8 private JDesktopPane theDesktop; 9 10 // set up GUI 11 public DesktopTest() 12 { 13 super( "Using a JDesktopPane" ); 14 15 // create menu bar, menu and menu item 16 JMenuBar bar = new JMenuBar(); 17 JMenu addMenu = new JMenu( "Add" ); 18 JMenuItem newFrame = new JMenuItem( "Internal Frame" ); 19 20 addMenu.add( newFrame ); 21 bar.add( addMenu ); 22 23 setJMenuBar( bar ); 24 25 // set up desktop 26 theDesktop = new JDesktopPane(); 27 getContentPane().add( theDesktop ); Manages JInternalFrame child windows displayed in JDesktopPane

50  2003 Prentice Hall, Inc. All rights reserved. Outline DesktopTest.jav a Line 30 Line 35 Lines 38-39 Lines 43-44 Line 47 28 29 // set up listener for newFrame menu item 30 newFrame.addActionListener( 31 32 new ActionListener() { // anonymous inner class 33 34 // display new internal window 35 public void actionPerformed( ActionEvent event ) { 36 37 // create internal frame 38 JInternalFrame frame = new JInternalFrame( 39 "Internal Frame", true, true, true, true ); 40 41 // attach panel to internal frame content pane 42 Container container = frame.getContentPane(); 43 MyJPanel panel = new MyJPanel(); 44 container.add( panel, BorderLayout.CENTER ); 45 46 // set size of internal frame to size of its contents 47 frame.pack(); 48 49 // attach internal frame to desktop and show it 50 theDesktop.add( frame ); 51 frame.setVisible( true ); 52 } 53 54 } // end anonymous inner class Handle event when user selects JMenuItem Invoked when user selects JMenuItem Create JInternalFrame, check parameters Use preferred size for window JPanel s can be added to JInternalFrame s

51  2003 Prentice Hall, Inc. All rights reserved. Outline DesktopTest.jav a 55 56 ); // end call to addActionListener 57 58 setSize( 600, 460 ); 59 setVisible( true ); 60 61 } // end constructor 62 63 public static void main( String args[] ) 64 { 65 DesktopTest application = new DesktopTest(); 66 application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 67 } 68 69 } // end class DesktopTest 70 71 // class to display an ImageIcon on a panel 72 class MyJPanel extends JPanel { 73 private ImageIcon imageIcon; 74 private String[] images = { "yellowflowers.png", "purpleflowers.png", 75 "redflowers.png", "redflowers2.png", "lavenderflowers.png" }; 76 77 // load image 78 public MyJPanel() 79 {

52  2003 Prentice Hall, Inc. All rights reserved. Outline DesktopTest.jav a 80 int randomNumber = ( int ) ( Math.random() * 5 ); 81 imageIcon = new ImageIcon( images[ randomNumber ] ); 82 } 83 84 // display imageIcon on panel 85 public void paintComponent( Graphics g ) 86 { 87 // call superclass paintComponent method 88 super.paintComponent( g ); 89 90 // display icon 91 imageIcon.paintIcon( this, g, 0, 0 ); 92 } 93 94 // return image dimensions 95 public Dimension getPreferredSize() 96 { 97 return new Dimension( imageIcon.getIconWidth(), 98 imageIcon.getIconHeight() ); 99 } 100 101 } // end class MyJPanel

53  2003 Prentice Hall, Inc. All rights reserved. Outline DesktopTest.jav a Internal Frames MinimizeMaximizeClose Minimized internal frames Position the mouse over any corner of a child window to resize the window (if resizing is allowed).

54  2003 Prentice Hall, Inc. All rights reserved. Outline DesktopTest.jav a

55  2003 Prentice Hall, Inc. All rights reserved. 55 14.11 JTabbedPane Arranges GUI components into layers –One layer visible at a time –Access each layer via a tab –JTabbedPane

56  2003 Prentice Hall, Inc. All rights reserved. Outline JTabbedPaneDemo.java Line 14 Line20 Line 27 1 // Fig. 14.13: JTabbedPaneDemo.java 2 // Demonstrating JTabbedPane. 3 import java.awt.*; 4 import javax.swing.*; 5 6 public class JTabbedPaneDemo extends JFrame { 7 8 // set up GUI 9 public JTabbedPaneDemo() 10 { 11 super( "JTabbedPane Demo " ); 12 13 // create JTabbedPane 14 JTabbedPane tabbedPane = new JTabbedPane(); 15 16 // set up pane11 and add it to JTabbedPane 17 JLabel label1 = new JLabel( "panel one", SwingConstants.CENTER ); 18 JPanel panel1 = new JPanel(); 19 panel1.add( label1 ); 20 tabbedPane.addTab( "Tab One", null, panel1, "First Panel" ); 21 22 // set up panel2 and add it to JTabbedPane 23 JLabel label2 = new JLabel( "panel two", SwingConstants.CENTER ); 24 JPanel panel2 = new JPanel(); 25 panel2.setBackground( Color.YELLOW ); 26 panel2.add( label2 ); 27 tabbedPane.addTab( "Tab Two", null, panel2, "Second Panel" ); Create a JTabbedPane Add the first panelAdd the second panel, the 1st parameter is the title, the second parameter is to set icon for the tab, the 3rd parameter is the component to add, the 4th parameter is the tooltip

57  2003 Prentice Hall, Inc. All rights reserved. Outline JTabbedPaneDemo.java Line 38 28 29 // set up panel3 and add it to JTabbedPane 30 JLabel label3 = new JLabel( "panel three" ); 31 JPanel panel3 = new JPanel(); 32 panel3.setLayout( new BorderLayout() ); 33 panel3.add( new JButton( "North" ), BorderLayout.NORTH ); 34 panel3.add( new JButton( "West" ), BorderLayout.WEST ); 35 panel3.add( new JButton( "East" ), BorderLayout.EAST ); 36 panel3.add( new JButton( "South" ), BorderLayout.SOUTH ); 37 panel3.add( label3, BorderLayout.CENTER ); 38 tabbedPane.addTab( "Tab Three", null, panel3, "Third Panel" ); 39 40 // add JTabbedPane to container 41 getContentPane().add( tabbedPane ); 42 43 setSize( 250, 200 ); 44 setVisible( true ); 45 46 } // end constructor 47 48 public static void main( String args[] ) 49 { 50 JTabbedPaneDemo tabbedPaneDemo = new JTabbedPaneDemo(); 51 tabbedPaneDemo.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 52 } 53 54 } // end class CardDeck Add the third panel

58  2003 Prentice Hall, Inc. All rights reserved. Outline JTabbedPaneDemo.java


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